The woes of AshleyMadison.com’s owners continued Thursday, with a second large release of internal data that security experts suspect is authentic.

An 18.5 GB file was released on file-sharing networks by a group called the Impact Team. The same group claimed responsibility for the initial breach last month of the website, which caters to those seeking extramarital affairs.

Because of the large file size, IDG News Service wasn’t able to take a look at the data. But David Kennedy, founder and CEO of the Ohio-based security company TrustedSec, said it appears to be legitimate.

His company had taken a brief look at the data. It contains what purports to be email from Avid Life Media’s CEO, Noel Biderman, as well as other employees.

It also contains the source code for all of Avid Life Media’s websites, which include CougarLife.com, EstablishedMen.com and others.

Kennedy said that’s particularly dangerous, since attackers can look at the source code and find weak points to conduct further intrusions.

The latest dump “is definitely a clear indication they had access to a lot more than the website itself,” he said. “They had access to the whole company.”

Avid Life Media, the owner of Ashley Madison and several other niche dating sites, did not have an immediate comment when contacted Thursday.

There may be clues in the new data and batches of emails of how the hackers got in. A common method for gaining access to a network is tricking an employee into clicking a malicious link or attachment with malware to infect a computer.

As security analysts look through the data, they could find a malware-laden email which would give further clues into how the breach began.

Avid Life Media has called the intrusion “an act of criminality" and on Tuesday said The Royal Canadian Mounted Police, the Ontario Provincial Police, the Toronto Police Services and the FBI are investigating the breach.

Although companies fall victim to data breaches every day, Ashley Madison has struck a particularly sensitive nerve given the risqué nature of the site.

The large tranche of data released earlier this week included names, email addresses, amount paid for subscription services, zip codes, GPS data and more.

More than 30 million people who registered with the site may be affected, although it’s widely believed some users used bogus data.

For its part, Impact Team has laid fairly low, choosing to announce its latest two leaks through a publication called Quantum Magazine.

It’s a text-only publication that is published on a so-called “hidden” website that uses the Tor anonymity system. Such websites can be viewed using the Tor browser. The advantage of setting up hidden websites is that it is harder, but not impossible, to find out its real IP address.

When the first 40 MB leak was released on July 19, Impact Team demanded that Avid Life Media shut down Ashley Madison and Established Men.

The group contended that if its demands weren’t met, much more data would be released, including source code repositories, financial records, internal documents and email.

Since that has come to pass, Avid Life Media is in a tough position and one in which few companies could probably recover from, Kennedy said.

“I would recommend they shut down at this point,” he said. “They are probably not going to survive this breach.”